Road carpeting machine



United States Patent Thomas Cecil Potts Blackburn, England Mar. 29, 1968 Dec. 29, 1970 Hudswell Clark and Company Limited Apr. 5, 1967 Great- Britain inventor Appl. No. Filed Patented Assignee Priority ROAD CARPETING MACHINE 1 Claim, 7 Drawing Figs.

US. Cl. int. Cl Field of Search E0lc 19/48 94/44, 45, 46

References Cited UNITED STATES PATENTS McCrery Barber l-lorning Apel et a1. Apel et al. Domeighetti Sayre Davin Pollitz et a1 Primary Examiner-Jacob L. Nackenoff Atrorney- Lawrence E. Laubscher ABSTRACT: Road carpeting machine having a hopper for carpeting material tarmacadam asphalt or concrete, a pair of conveyors to discharge the material from the hopper and a screed and spreader unit to spread the laid material.

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INVENTOR PATENTED DEC29 I978 SHEET 3 [1F 6 INVENTOR ATTORNEY PATENTED 0&2291970- I SHEET 8 0F 6 I I l I INVLNTOR ATTORNEY PATENTEU DEB29 19m SHEET 5 [IF 6 C. Pm

INVENTOR v BY W 8 m AYTORNKY PATENTEn'uzczs 19m SHE EI 6 OF 6 INVENTOR BY mam AT T'ORNLY ROAD CARPETING MACHINE This invention is concerned with improvements in and relating to road carpeting machines for laying surfaces of, for ex ample tarmacadam, asphalt, concrete or the like on roads or pavements.

According to the present invention there is provided a road carpeting machine which comprises a main chassis having ground engaging support means for movement of the chassis, a subchassis extending rearwardly from a pivotal mounting on the main chassis adjacent the front of the main chassis, a screed and spreader plate assembly supported by the subchassis and located rearwardly of the rearmost ground engaging support, a hopper on the main chassis, a pair of conveyors mounted upon the main chassis and extending from a hopper outlet rearwardly to discharge carpeting material on to the ground forward of the screed and spreader plate assembly, a variable speed drive to each conveyor and a control at an operators station on the machine operable by the operator to discharge carpeting material at desired rates according to the operating conditions.

A variable speed delivery of the material is provided so that should the material tend to pile up on one side or one side become starved, perhaps due to a change of camber, the operator can instantly and finely adjust the operation of the conveyors to correct the situation.

In a preferred form of the machine there is a single engine mounted on the chassis to drive a hydrostatic transmission unit which supplies two hydraulic conveyor drive motors by way of the operators control and drives two rear wheels through a rear axle incorporating a differential gear unit.

In order that the present invention may be well understood there will now be described an embodiment thereof, given by way of example only, reference being had to the accompanying drawings in which:

FIG. 1 is a side elevation of a carpeting machine;

FIG. 2 is a plan view ofthe machine of FIG. 1;

FIG. 3 is a rear view of the machine of FIG. 1;

FIG. 4 is a cross section of one of the conveyors;

FIG. 5 is a perspective view of part of the shielding of the conveyor;

FIG. 6 is a detail view of one side of the auger assembly, and

FIG. 7 is a plan view of a machine modified for carpeting, for example, pavements.

The machine comprises a main chassis 1 having front road wheels 2 and rear road wheels 3. Toward the front of the main chassis is a hopper 4 for carpeting material, and pivotally mounted at 5 on each side of the main chassis adjacent the front of that chassis is an arm 6 of a subchassis. The arms extend rearwardly, are cranked to pass over the rear wheel mountings and carry at the rear ends, behind the rear wheels, a screed and spreader plate assembly 7.

To drive the machine forward an engine 8 is mounted on the main chassis, and is coupled to a hydrostatic transmission element 10 which in turn is coupled to a differential gear 11. This gear 11 may be controlled to lock the two output shafts, whose casings are shown at 12m to allow relative rotation of the shafts. Each of those shafts carries a sprocket in a chain casing 13, coupled by a driving chain to a wheel sprocket fast with a rear wheel stub axle. By this drive arrangement, the machine can be driven forward at variable speed with the rear wheels locked or free relative to one another, depending on the work in progress. Steering is by any suitable device, preferably powered, operable on the front wheels.

The hopper is formed of walls 15, defining a storage space above a part of the upper flight of two conveyors l7, 18, which will discharge material at the rear of the main chassis ahead of the screed and spreader plate assembly 7. Each conveyor comprises a plate 19 mounted on a supporting frame 20 on the main chassis, the plate extending laterally beyond the sides of the frame work over the upper flights of two endless chains 21, each running on a front sprocket 23, and a rear sprocket not shown. At intervals lugs 24 are bolted to each chain and these lugs engage flanges 25 of conveyor slats 26. The upper flight of each conveyor lies between a main chassis side member 27 and a divider 28 and shields 29 are mounted on the main chassis and divider to prevent material fouling the chain which is further protected by lying under the lateral margins of the plate. To further protect the chains, the lower flights run in channel elements 30 (FIG. 5). Each conveyor is driven through its rear sprocket by a hydraulic motor 31 coupled to a variable delivery pump being one of a series of such pumps driven by the engine and controls are provided at the operators platform 32 so that the conveyor speeds can be infinitely adjusted relative to one another and to forward speed to provide the required amount of material to give the desired carpet thickness both longitudinally and laterally.

Rearward of the discharge position of the conveyors is an auger assembly 33 comprising two augers 35, 36 each supported in bearings 37 and each driven through a chain 38 by a hydraulic motor 39 coupled to another one of the series of pumps so that the augers are independently driven at infinitely variable speeds, suitable controls being provided at the operators station 32. By providing an independent and infinitely variable drive to the augers, material discharged by the conveyors can be accurately spread laterally. The drives are additionally reversible so that if necessary excess material discharging to one side of the machine from the conveyors can be moved across to the other side of the machine by making the augers work in unison rather than oppositely.

Each scroll is provided with an extension facility in that the stem 40 of each auger is hollow at its outer end which runs in a bearing 37. Normally the hollow stem is closed by a plug 41, secured by a pin 42. To lengthen the assembly the plug is removed and a coupling member 43 of an auxiliary auger 44 is inserted and made fast by pin 42.

The screed and spreader plate assembly comprises a box structure 45 which is pivotally suspended at the forward part on hangers 46 and at the rear part by rods 47. The latter are threadedly received by trunnions 48 pivotally carried by the arms, an adjusting handle 49 being provided on each rod. The hangers 46 are telescopic, the length being adjustable by handles 50. The base 51 of the boxlike structure extends the full width of the assembly and forms a screed plate which irons out the surface, the full weight of the subchassis and scroll being supported by the screed plate. Ahead of the screed plate is a concave spreader plate 51a which serves to give a rough spreading action and between the screed plate and the spreader plate is a tamper plate 52. This plate is suspended by coupling members 53 from eccentrics on a shaft 55 carried in bearings 56. A belt or chain drive 57 to the shaft is driven by a hydraulic motor 58 again powered from another one of the series of pumps. Thus an independent infinitely variable drive is provided for the tamper plate which will subject the surface product produced by the spreader plate to a compression before the screed plate gives the final finish. If desired a heater, such as a gas or oil burner 59, may be mounted on the boxlike structure to heat the screed plate and prevent the material sticking to that plate. As in the case of the scroll assembly, provision is made to extend the boxlike structure laterally. Thus extension boxes 60 are pivotally secured to each end of the boxlike structure about vertical pivot axes 61. The boxlike structure carries cam tracks 62 which cause the extension boxes to rise as they move to the inoperative position shown in FIG. 1. The front 63 of each extension. box will form an extension of the screed plate and a guide peg 64 is provided for engaging an aperture in the boxlike structure.

In order to raise the subchassis when the machine is to travel idle, a hydraulic ram is provided on the main chassis coupled to the subchassis through a lost motion link so that when the subchassis is in work it is free to rise relative to the main chassis.

In operation the machine is loaded from a dump truck backed-up to the front of the hopper 4. In practice the truck may continue unloading while the machine is advancing, rollers 65 being provided at the front of the machine which will bear against the rear wheels of the truck.

The conveyors 17, 18 are set in motion at the desired speed and the slats 26 draw material from the hopper over the plates 29 and discharge the material ahead of the augers 35, 36 which distribute the material sideways of the machine. The spreader plate 510 roughly spreads the material, the tamper plate 52 compresses it and the screed plate 51 gives a final finish to the surface. If the conveyors are required to discharge more to one side than the other the drives are regulated. The later The lateral grading of the finished surface and the thickness of the carpet can be regulated by adjustment of the hangers 46 and rods 47. To provide a transverse slope or camber assuming the base to be horizontal, the screed plate assembly would be elevated on that side of the machine adjacent the crown of the camber. Alternatively the screed plate may be higher on that side remote from an existing crown where the camber is to be reduced. it is preferred that the screed plate should be adjustable in height at the center so that a high point can be provided along the center of the carpet to produce a crown on the road surface. In this case the walls and top of the boxlike structure are split longitudinally along the machine center line at 66 (FIG. 2) while the base remains continuous transversely of the machine and a pair of horizontal adjuster screws 67 coupled by a chain 67a for simultaneous rotation.

Referring to FIG. 7, there is shown a modified machine which is primarily intended for work in confined conditions, e.g., on walks or pavements. The modified machine has a hopper 68 shown in the loading or transverse position the hopper being longer and narrower than previously so that it is within the limits of the wheel base. When in the fore and aft or work position it has a capacity of the same order as the machine previously described and is mounted for rotation about axis 69 so that the hopper can be moved to the full line position for loading from the side of the machine whilst on a pavement and can then be rotated to the fore and aft position for working. For the rest the machine is the same as that previously described.

In place of the cam tracks 62 it may be preferred to mount jack bolts on the extension boxes to lift these when they have been swung into the inoperative position.

lclaim:

1. Apparatus for distributing road carpeting material upon a generally horizontal road surface, comprising:

a. main chassis means 1 including ground-engaging support means for transporting said main chassis in a given direction, said main chassis means including on its upper surface a first horizontal longitudinally extending plate b. subchassis means 6 pivotally connected with the front portion of said main chassis means;

c. a screed and spreader plate assembly 7 connected with said subchassis means rearwardly of said main chassis ground-engaging support means;

(1. hopper means 4 mounted on said main chassis means for discharging said carpeting material onto said plate;

e. a pair of endless conveyor means l7, 18 18) for conveying carpeting material rearwardly from said hopper means to said screed and spreader plate assembly, each of said conveyor means including:

i. an endless succession of horizontal slats 26 having upper and lower flights, said slats extending transversely of said main chassis means, said upper flight of slats being supported by, and extending at each end beyond the edges of, said plate,

2. a pair of laterally spaced endless drive chains 21 extending longitudinally of said main chassis beneath and spaced inwardly from the lateral edges of said plate, 3. flange means 25 connected with the ends of said slats and extending inwardly beyond said plate toward said drive chains, respectively,

. lug means 24 connecting said chains with said flange means, respectively, and channel means 3 ll'lClUdll'lg a pair of outwardly directed channel elements connected with said plate between, and arranged to receive the lower flights of, said chains, respectively;

f. stationary shield means connected with said main chassis above the end portions of the upper flights of said slats, said stationary shield means cooperating with said plate and said channel elements to prevent carpeting material from lodging in said drive chains;

g. auger means connected with said main chassis frame rearwardly of said conveyor means, said auger means extending transversely of said main chassis adjacent the rear end of said conveyor means; and

h. means for driving said conveyor means and said auger means, comprising a main motor carried by said main chassis means, hydraulic motor means driven by said main motor means, and control means for controlling the operation of said conveyor means and said auger means.

Lit 

